Over-the-range microwave appliances are generally mounted above a cooktop of an oven range appliance. In addition to providing for heating of food and beverage items, certain over-the-range microwave appliances include a circulation system. When activated, the circulation system can draw fumes, smoke, grease, and/or steam away from the cooktop of the oven range appliance. Circulation systems generally include a fan for drawing a flow of air into the circulation system and a grease filter for trapping grease entering the circulation system. Certain over-the-range microwave appliances also include air filters for filtering air passing through the microwave appliances' circulation systems. The circulation assembly's air filter can assist with removing dust, particulates, and/or other undesirable substances from air passing therethrough.
Over-the-range microwave appliances generally activate the circulation system's fan on demand and/or for a predetermined time interval in order to filter the air with the circulation system's air filter. After the predetermined time interval elapses, the fan is deactivated and the circulation system stops filtering air. A user can also manually deactivate the fan prior to the predetermined time interval elapsing in order to stop filtering air with the circulation system.
After a period of use, such air filters can require changing. For example, charcoal air filters fill with odor molecules, etc., during use and eventually will cease filtering. Currently, however, consumers do not receive any feedback that the air filter may require changing. Thus, some consumers leave the air filter in for too long or neglect to change the air filter at all, while others change the air filter too soon.
Accordingly, a microwave appliance with features for indicating a need for an air filter change would be desired. In particular, a microwave appliance with features that reduce the risk of prolonged air filter use would be advantageous.